Soil pH

Benchmark Value

No specific value — see range

Range: 6.5 to 9 pH

Optimal Range: 6.5 to 9

Direction: Higher is desirable ↑

Form: OptimalRange

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary LowerThreshold Guard OptimalRange Guard LowerThreshold Guard UpperThreshold Guard OptimalRange Guard Point Guard LowerThreshold Guard UpperThreshold Guard Point Guard

Evidence & Context

The Reference Value for Soil pH is the range 6.5 – 9.0 (measured in water).

Metric Definition:

Soil pH measured in water as a proxy for soil ecosystem pH in the Arid Inland Floodplains biome.

Benchmark Definition:

The natural pH range for soils in healthy, protected arid floodplain ecosystems based on water quality data from a high-quality reference system.

Justification:

Derived from direct measurements from the Diamantina-Georgina catchment, corroborated by continental-scale soil surveys and consistent with pedogenesis principles in arid environments.

Sources (2)

Preview of (PDF) The pH of Australian soils: field results from a national survey - ResearchGate, accessed July 25, 2025,

(PDF) The pH of Australian soils: field results from a national survey - ResearchGate, accessed July 25, 2025, Journal

Soil pH | Environment, land and water - Queensland Government, accessed August 28, 2025,

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Preview of Water and sediment quality in the Diamantina-Georgina River catchment, Lake Eyre Basin

Water and sediment quality in the Diamantina-Georgina River catchment, Lake Eyre Basin Journal

Water quality in the Georgina-Diamantina River catchment

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Supporting Sources (8)

Additional references from the underlying research that informed this benchmark.

ASC - VERTOSOLS - Soil Science Australia

Contextual Support

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase

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Australian Soil Classification edition 3 - CALCAROSOLS

Contextual Support Government

Soil Characteristics and Management Options | VRO - Victorian Resources Online

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Ecological impacts of flood mitigation and drainage in coastal lowlands - AustLII

Contextual Support

Ecological impacts of flood mitigation and drainage in coastal lowlands - AustLII

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National Guidance on Acid Sulfate Soils - Water Quality Australia

Contextual Support Journal

Managing soils - Department of Primary Industries and Regional Development

View Source

Soil Constraints in an Arid Environment - Encyclopedia.pub

Contextual Support GreyLiterature

Soil Constraints in an Arid Environment - Encyclopedia.pub, accessed July 27, 2025,

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Soil pH - SA | Fact Sheets | soilquality.org.au

Contextual Support Government

Soil pH - SA | Fact Sheets | soilquality.org.au, accessed July 30, 2025,

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Victorian Resources Online | Resources | Support and resources ...

Contextual Support Government

Structural controls on the orientation of erosion gullies in mid-western New South Wales, Australia, accessed July 22, 2025

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Water and sediment quality in the Diamantina-Georgina River ..., accessed July 21, 2025,

Contextual Support Journal

Water and sediment quality in the Diamantina-Georgina River ..., accessed July 21, 2025,

View Source

Benchmark Value

Scoring Curve

Contributing Benchmarks

Evidence & Context

Sources (2)

Supporting Sources (8)

Context

Lifecycle

Notes

Related Benchmarks